The proposed research is designed to examine demographic change and stability in a small rural Swiss village over a 300 year period, and to evaluate the role of population variables in the ecosystem of a local community. It will be based on genealogical data and vital statistics covering more than 5700 individuals as well as supporting ethnographic material on household composition, agricultrual techniques, work organization, land ownership, inheritance, marriage patterns, and values relating to reproduction. Preliminary analysis has suggested that strictly limited resources and a simple, unchanging subsistence technology in an environment restricted by the scarcity of water and level land and the shortness of the Alpine growing season have created a situation of longstanding population pressure. Major factors influencing the homeostasis or slow growth of village population have been (1) mortality, (2) decreased fertility due in part to high age of marriage, (3) celibacy, (4) temporary or permanent out-migration. It is hypothesized that each of these factors played a significant role in regulating local population numbers and composition in terms of the specifically limited possibilities for subsistence and in the absence of modern birth control techniques. With changes in external factors affecting the village (e.g., improved nutrition, medical and welfare services, opportunities for wage work), the differential effect of the four factors on population equilibrium through time may be measured. Research will include the collecting of more complete demographic data from Swiss documentary sources, preparation of the material for computer processing, computer programming, and the analysis of the demographic indices obtained.